States of Matter
What state of matter has a definite shape and volume?
Solid — has definite shape and volume.
What phase change is the transition from solid to liquid?
Melting — solid to liquid.
Is color a physical or chemical property? Explain.
Physical property — color can be observed without changing the substance.
Is breaking a glass a physical or chemical change? Why?
Physical change — breaking glass changes shape but not composition.
What pH value indicates a substance is acidic?
pH less than 7.
In which state of matter do particles move freely and fill the container?
Gas — particles move freely and fill the container.
During vaporization, does particle speed increase or decrease? Explain.
Increase — particles gain energy and move faster during vaporization.
What is a chemical property? Give an example.
Chemical property describes how a substance reacts with others; example: flammability.
Name two signs that a physical change has occurred.
Signs include change in size and shape
What is the difference between a compound and a mixture?
Compound is chemically combined substances; mixture is physically combined substances.
Describe the particle spacing and movement in a liquid.
Particles are close but can slide past each other; they move faster than solids but slower than gases.
What happens to the energy of particles during condensation?
Energy decreases — particles lose energy and slow down during condensation.
Calculate the density of an object with mass 45 g and volume 15 mL using water displacement.
Density = mass/volume = 45 g/15 mL=3 g/mL
Burning wood is an example of what type of change? Explain your answer.
Chemical change — burning wood produces new substances (ash, gases).
Identify whether salt water is a homogeneous or heterogeneous mixture.
Homogeneous mixture — salt water is uniform throughout.
Which state of matter has particles sliding past each other?
Liquid - particles slide past each other
Compare particle spacing in melting versus freezing.
Melting: particles move farther apart; Freezing: particles come closer together.
A rock displaces water from 15 mL to 35 mL and has a mass of 50 g. What is its density?
Density = 50 g/20 mL=2.5
Is dissolving salt in water a physical or chemical change? Explain.
Physical change — dissolving salt changes appearance but salt can be recovered.
Is baking soda a pure substance or a mixture? Explain.
Pure substance — baking soda is a compound with a fixed composition.
(Daily Double): Explain why gases are the fastest, but solids and liquids are not.
Gases have the most amount of energy between solids, liquids, and gases
(Daily Double): Explain the energy changes and particle movement during sublimation.
Sublimation: particles gain enough energy to change from solid directly to gas, increasing speed and spacing without becoming liquid.
Explain why density is a physical property.
Density is physical because it describes a measurable characteristic without changing the substance’s identity.
Describe evidence that would help you identify a chemical change.
Evidence includes color or temperature changes, gas bubbles, precipitate formation, or light emission.
Explain how acids and bases react together.
Acids and bases neutralize each other.